src/ignore.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "ignore.h"
   9
  10 #include "git2/ignore.h"
  11 #include "common.h"
  12 #include "attrcache.h"
  13 #include "path.h"
  14 #include "config.h"
  15 #include "fnmatch.h"
  16
  17 #define GIT_IGNORE_INTERNAL             "[internal]exclude"
  18
  19 #define GIT_IGNORE_DEFAULT_RULES ".\n..\n.git\n"
  20
  21 /**
  22  * A negative ignore pattern can negate a positive one without
  23  * wildcards if it is a basename only and equals the basename of
  24  * the positive pattern. Thus
  25  *
  26  * foo/bar
  27  * !bar
  28  *
  29  * would result in foo/bar being unignored again while
  30  *
  31  * moo/foo/bar
  32  * !foo/bar
  33  *
  34  * would do nothing. The reverse also holds true: a positive
  35  * basename pattern can be negated by unignoring the basename in
  36  * subdirectories. Thus
  37  *
  38  * bar
  39  * !foo/bar
  40  *
  41  * would result in foo/bar being unignored again. As with the
  42  * first case,
  43  *
  44  * foo/bar
  45  * !moo/foo/bar
  46  *
  47  * would do nothing, again.
  48  */
  49 static int does_negate_pattern(git_attr_fnmatch *rule, git_attr_fnmatch *neg)
  50 {
  51         int (*cmp)(const char *, const char *, size_t);
  52         git_attr_fnmatch *longer, *shorter;
  53         char *p;
  54
  55         if ((rule->flags & GIT_ATTR_FNMATCH_NEGATIVE) != 0
  56             || (neg->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0)
  57                 return false;
  58
  59         if (neg->flags & GIT_ATTR_FNMATCH_ICASE)
  60                 cmp = git__strncasecmp;
  61         else
  62                 cmp = git__strncmp;
  63
  64         /* If lengths match we need to have an exact match */
  65         if (rule->length == neg->length) {
  66                 return cmp(rule->pattern, neg->pattern, rule->length) == 0;
  67         } else if (rule->length < neg->length) {
  68                 shorter = rule;
  69                 longer = neg;
  70         } else {
  71                 shorter = neg;
  72                 longer = rule;
  73         }
  74
  75         /* Otherwise, we need to check if the shorter
  76          * rule is a basename only (that is, it contains
  77          * no path separator) and, if so, if it
  78          * matches the tail of the longer rule */
  79         p = longer->pattern + longer->length - shorter->length;
  80
  81         if (p[-1] != '/')
  82                 return false;
  83         if (memchr(shorter->pattern, '/', shorter->length) != NULL)
  84                 return false;
  85
  86         return cmp(p, shorter->pattern, shorter->length) == 0;
  87 }
  88
  89 /**
  90  * A negative ignore can only unignore a file which is given explicitly before, thus
  91  *
  92  *    foo
  93  *    !foo/bar
  94  *
  95  * does not unignore 'foo/bar' as it's not in the list. However
  96  *
  97  *    foo/<star>
  98  *    !foo/bar
  99  *
 100  * does unignore 'foo/bar', as it is contained within the 'foo/<star>' rule.
 101  */
 102 static int does_negate_rule(int *out, git_vector *rules, git_attr_fnmatch *match)
 103 {
 104         int error = 0, fnflags;
 105         size_t i;
 106         git_attr_fnmatch *rule;
 107         char *path;
 108         git_buf buf = GIT_BUF_INIT;
 109
 110         *out = 0;
 111
 112         fnflags = FNM_PATHNAME;
 113         if (match->flags & GIT_ATTR_FNMATCH_ICASE)
 114                 fnflags |= FNM_IGNORECASE;
 115
 116         /* path of the file relative to the workdir, so we match the rules in subdirs */
 117         if (match->containing_dir) {
 118                 git_buf_puts(&buf, match->containing_dir);
 119         }
 120         if (git_buf_puts(&buf, match->pattern) < 0)
 121                 return -1;
 122
 123         path = git_buf_detach(&buf);
 124
 125         git_vector_foreach(rules, i, rule) {
 126                 if (!(rule->flags & GIT_ATTR_FNMATCH_HASWILD)) {
 127                         if (does_negate_pattern(rule, match)) {
 128                                 error = 0;
 129                                 *out = 1;
 130                                 goto out;
 131                         }
 132                         else
 133                                 continue;
 134                 }
 135
 136                 git_buf_clear(&buf);
 137                 if (rule->containing_dir)
 138                         git_buf_puts(&buf, rule->containing_dir);
 139                 git_buf_puts(&buf, rule->pattern);
 140
 141                 if (git_buf_oom(&buf))
 142                         goto out;
 143
 144                 if ((error = p_fnmatch(git_buf_cstr(&buf), path, fnflags)) < 0) {
 145                         git_error_set(GIT_ERROR_INVALID, "error matching pattern");
 146                         goto out;
 147                 }
 148
 149                 /* if we found a match, we want to keep this rule */
 150                 if (error != FNM_NOMATCH) {
 151                         *out = 1;
 152                         error = 0;
 153                         goto out;
 154                 }
 155         }
 156
 157         error = 0;
 158
 159 out:
 160         git__free(path);
 161         git_buf_dispose(&buf);
 162         return error;
 163 }
 164
 165 static int parse_ignore_file(
 166         git_repository *repo, git_attr_file *attrs, const char *data)
 167 {
 168         int error = 0;
 169         int ignore_case = false;
 170         const char *scan = data, *context = NULL;
 171         git_attr_fnmatch *match = NULL;
 172
 173         if (git_repository__cvar(&ignore_case, repo, GIT_CVAR_IGNORECASE) < 0)
 174                 git_error_clear();
 175
 176         /* if subdir file path, convert context for file paths */
 177         if (attrs->entry &&
 178                 git_path_root(attrs->entry->path) < 0 &&
 179                 !git__suffixcmp(attrs->entry->path, "/" GIT_IGNORE_FILE))
 180                 context = attrs->entry->path;
 181
 182         if (git_mutex_lock(&attrs->lock) < 0) {
 183                 git_error_set(GIT_ERROR_OS, "failed to lock ignore file");
 184                 return -1;
 185         }
 186
 187         while (!error && *scan) {
 188                 int valid_rule = 1;
 189
 190                 if (!match && !(match = git__calloc(1, sizeof(*match)))) {
 191                         error = -1;
 192                         break;
 193                 }
 194
 195                 match->flags =
 196                     GIT_ATTR_FNMATCH_ALLOWSPACE |
 197                     GIT_ATTR_FNMATCH_ALLOWNEG |
 198                     GIT_ATTR_FNMATCH_NOLEADINGDIR;
 199
 200                 if (!(error = git_attr_fnmatch__parse(
 201                         match, &attrs->pool, context, &scan)))
 202                 {
 203                         match->flags |= GIT_ATTR_FNMATCH_IGNORE;
 204
 205                         if (ignore_case)
 206                                 match->flags |= GIT_ATTR_FNMATCH_ICASE;
 207
 208                         scan = git__next_line(scan);
 209
 210                         /*
 211                          * If a negative match doesn't actually do anything,
 212                          * throw it away. As we cannot always verify whether a
 213                          * rule containing wildcards negates another rule, we
 214                          * do not optimize away these rules, though.
 215                          * */
 216                         if (match->flags & GIT_ATTR_FNMATCH_NEGATIVE
 217                             && !(match->flags & GIT_ATTR_FNMATCH_HASWILD))
 218                                 error = does_negate_rule(&valid_rule, &attrs->rules, match);
 219
 220                         if (!error && valid_rule)
 221                                 error = git_vector_insert(&attrs->rules, match);
 222                 }
 223
 224                 if (error != 0 || !valid_rule) {
 225                         match->pattern = NULL;
 226
 227                         if (error == GIT_ENOTFOUND)
 228                                 error = 0;
 229                 } else {
 230                         match = NULL; /* vector now "owns" the match */
 231                 }
 232         }
 233
 234         git_mutex_unlock(&attrs->lock);
 235         git__free(match);
 236
 237         return error;
 238 }
 239
 240 static int push_ignore_file(
 241         git_ignores *ignores,
 242         git_vector *which_list,
 243         const char *base,
 244         const char *filename)
 245 {
 246         int error = 0;
 247         git_attr_file *file = NULL;
 248
 249         error = git_attr_cache__get(
 250                 &file, ignores->repo, NULL, GIT_ATTR_FILE__FROM_FILE,
 251                 base, filename, parse_ignore_file);
 252         if (error < 0)
 253                 return error;
 254
 255         if (file != NULL) {
 256                 if ((error = git_vector_insert(which_list, file)) < 0)
 257                         git_attr_file__free(file);
 258         }
 259
 260         return error;
 261 }
 262
 263 static int push_one_ignore(void *payload, const char *path)
 264 {
 265         git_ignores *ign = payload;
 266         ign->depth++;
 267         return push_ignore_file(ign, &ign->ign_path, path, GIT_IGNORE_FILE);
 268 }
 269
 270 static int get_internal_ignores(git_attr_file **out, git_repository *repo)
 271 {
 272         int error;
 273
 274         if ((error = git_attr_cache__init(repo)) < 0)
 275                 return error;
 276
 277         error = git_attr_cache__get(
 278                 out, repo, NULL, GIT_ATTR_FILE__IN_MEMORY, NULL, GIT_IGNORE_INTERNAL, NULL);
 279
 280         /* if internal rules list is empty, insert default rules */
 281         if (!error && !(*out)->rules.length)
 282                 error = parse_ignore_file(repo, *out, GIT_IGNORE_DEFAULT_RULES);
 283
 284         return error;
 285 }
 286
 287 int git_ignore__for_path(
 288         git_repository *repo,
 289         const char *path,
 290         git_ignores *ignores)
 291 {
 292         int error = 0;
 293         const char *workdir = git_repository_workdir(repo);
 294         git_buf infopath = GIT_BUF_INIT;
 295
 296         assert(repo && ignores && path);
 297
 298         memset(ignores, 0, sizeof(*ignores));
 299         ignores->repo = repo;
 300
 301         /* Read the ignore_case flag */
 302         if ((error = git_repository__cvar(
 303                         &ignores->ignore_case, repo, GIT_CVAR_IGNORECASE)) < 0)
 304                 goto cleanup;
 305
 306         if ((error = git_attr_cache__init(repo)) < 0)
 307                 goto cleanup;
 308
 309         /* given a unrooted path in a non-bare repo, resolve it */
 310         if (workdir && git_path_root(path) < 0) {
 311                 git_buf local = GIT_BUF_INIT;
 312
 313                 if ((error = git_path_dirname_r(&local, path)) < 0 ||
 314                     (error = git_path_resolve_relative(&local, 0)) < 0 ||
 315                     (error = git_path_to_dir(&local)) < 0 ||
 316                     (error = git_buf_joinpath(&ignores->dir, workdir, local.ptr)) < 0)
 317                 {;} /* Nothing, we just want to stop on the first error */
 318                 git_buf_dispose(&local);
 319         } else {
 320                 error = git_buf_joinpath(&ignores->dir, path, "");
 321         }
 322         if (error < 0)
 323                 goto cleanup;
 324
 325         if (workdir && !git__prefixcmp(ignores->dir.ptr, workdir))
 326                 ignores->dir_root = strlen(workdir);
 327
 328         /* set up internals */
 329         if ((error = get_internal_ignores(&ignores->ign_internal, repo)) < 0)
 330                 goto cleanup;
 331
 332         /* load .gitignore up the path */
 333         if (workdir != NULL) {
 334                 error = git_path_walk_up(
 335                         &ignores->dir, workdir, push_one_ignore, ignores);
 336                 if (error < 0)
 337                         goto cleanup;
 338         }
 339
 340         if ((error = git_repository_item_path(&infopath,
 341                         repo, GIT_REPOSITORY_ITEM_INFO)) < 0)
 342                 goto cleanup;
 343
 344         /* load .git/info/exclude */
 345         error = push_ignore_file(
 346                 ignores, &ignores->ign_global,
 347                 infopath.ptr, GIT_IGNORE_FILE_INREPO);
 348         if (error < 0)
 349                 goto cleanup;
 350
 351         /* load core.excludesfile */
 352         if (git_repository_attr_cache(repo)->cfg_excl_file != NULL)
 353                 error = push_ignore_file(
 354                         ignores, &ignores->ign_global, NULL,
 355                         git_repository_attr_cache(repo)->cfg_excl_file);
 356
 357 cleanup:
 358         git_buf_dispose(&infopath);
 359         if (error < 0)
 360                 git_ignore__free(ignores);
 361
 362         return error;
 363 }
 364
 365 int git_ignore__push_dir(git_ignores *ign, const char *dir)
 366 {
 367         if (git_buf_joinpath(&ign->dir, ign->dir.ptr, dir) < 0)
 368                 return -1;
 369
 370         ign->depth++;
 371
 372         return push_ignore_file(
 373                 ign, &ign->ign_path, ign->dir.ptr, GIT_IGNORE_FILE);
 374 }
 375
 376 int git_ignore__pop_dir(git_ignores *ign)
 377 {
 378         if (ign->ign_path.length > 0) {
 379                 git_attr_file *file = git_vector_last(&ign->ign_path);
 380                 const char *start = file->entry->path, *end;
 381
 382                 /* - ign->dir looks something like "/home/user/a/b/" (or "a/b/c/d/")
 383                  * - file->path looks something like "a/b/.gitignore
 384                  *
 385                  * We are popping the last directory off ign->dir.  We also want
 386                  * to remove the file from the vector if the popped directory
 387                  * matches the ignore path.  We need to test if the "a/b" part of
 388                  * the file key matches the path we are about to pop.
 389                  */
 390
 391                 if ((end = strrchr(start, '/')) != NULL) {
 392                         size_t dirlen = (end - start) + 1;
 393                         const char *relpath = ign->dir.ptr + ign->dir_root;
 394                         size_t pathlen = ign->dir.size - ign->dir_root;
 395
 396                         if (pathlen == dirlen && !memcmp(relpath, start, dirlen)) {
 397                                 git_vector_pop(&ign->ign_path);
 398                                 git_attr_file__free(file);
 399                         }
 400                 }
 401         }
 402
 403         if (--ign->depth > 0) {
 404                 git_buf_rtruncate_at_char(&ign->dir, '/');
 405                 git_path_to_dir(&ign->dir);
 406         }
 407
 408         return 0;
 409 }
 410
 411 void git_ignore__free(git_ignores *ignores)
 412 {
 413         unsigned int i;
 414         git_attr_file *file;
 415
 416         git_attr_file__free(ignores->ign_internal);
 417
 418         git_vector_foreach(&ignores->ign_path, i, file) {
 419                 git_attr_file__free(file);
 420                 ignores->ign_path.contents[i] = NULL;
 421         }
 422         git_vector_free(&ignores->ign_path);
 423
 424         git_vector_foreach(&ignores->ign_global, i, file) {
 425                 git_attr_file__free(file);
 426                 ignores->ign_global.contents[i] = NULL;
 427         }
 428         git_vector_free(&ignores->ign_global);
 429
 430         git_buf_dispose(&ignores->dir);
 431 }
 432
 433 static bool ignore_lookup_in_rules(
 434         int *ignored, git_attr_file *file, git_attr_path *path)
 435 {
 436         size_t j;
 437         git_attr_fnmatch *match;
 438
 439         git_vector_rforeach(&file->rules, j, match) {
 440                 if (match->flags & GIT_ATTR_FNMATCH_DIRECTORY &&
 441                     path->is_dir == GIT_DIR_FLAG_FALSE)
 442                         continue;
 443                 if (git_attr_fnmatch__match(match, path)) {
 444                         *ignored = ((match->flags & GIT_ATTR_FNMATCH_NEGATIVE) == 0) ?
 445                                 GIT_IGNORE_TRUE : GIT_IGNORE_FALSE;
 446                         return true;
 447                 }
 448         }
 449
 450         return false;
 451 }
 452
 453 int git_ignore__lookup(
 454         int *out, git_ignores *ignores, const char *pathname, git_dir_flag dir_flag)
 455 {
 456         unsigned int i;
 457         git_attr_file *file;
 458         git_attr_path path;
 459
 460         *out = GIT_IGNORE_NOTFOUND;
 461
 462         if (git_attr_path__init(
 463                 &path, pathname, git_repository_workdir(ignores->repo), dir_flag) < 0)
 464                 return -1;
 465
 466         /* first process builtins - success means path was found */
 467         if (ignore_lookup_in_rules(out, ignores->ign_internal, &path))
 468                 goto cleanup;
 469
 470         /* next process files in the path */
 471         git_vector_foreach(&ignores->ign_path, i, file) {
 472                 if (ignore_lookup_in_rules(out, file, &path))
 473                         goto cleanup;
 474         }
 475
 476         /* last process global ignores */
 477         git_vector_foreach(&ignores->ign_global, i, file) {
 478                 if (ignore_lookup_in_rules(out, file, &path))
 479                         goto cleanup;
 480         }
 481
 482 cleanup:
 483         git_attr_path__free(&path);
 484         return 0;
 485 }
 486
 487 int git_ignore_add_rule(git_repository *repo, const char *rules)
 488 {
 489         int error;
 490         git_attr_file *ign_internal = NULL;
 491
 492         if ((error = get_internal_ignores(&ign_internal, repo)) < 0)
 493                 return error;
 494
 495         error = parse_ignore_file(repo, ign_internal, rules);
 496         git_attr_file__free(ign_internal);
 497
 498         return error;
 499 }
 500
 501 int git_ignore_clear_internal_rules(git_repository *repo)
 502 {
 503         int error;
 504         git_attr_file *ign_internal;
 505
 506         if ((error = get_internal_ignores(&ign_internal, repo)) < 0)
 507                 return error;
 508
 509         if (!(error = git_attr_file__clear_rules(ign_internal, true)))
 510                 error = parse_ignore_file(
 511                         repo, ign_internal, GIT_IGNORE_DEFAULT_RULES);
 512
 513         git_attr_file__free(ign_internal);
 514         return error;
 515 }
 516
 517 int git_ignore_path_is_ignored(
 518         int *ignored,
 519         git_repository *repo,
 520         const char *pathname)
 521 {
 522         int error;
 523         const char *workdir;
 524         git_attr_path path;
 525         git_ignores ignores;
 526         unsigned int i;
 527         git_attr_file *file;
 528         git_dir_flag dir_flag = GIT_DIR_FLAG_UNKNOWN;
 529
 530         assert(repo && ignored && pathname);
 531
 532         workdir = git_repository_workdir(repo);
 533
 534         memset(&path, 0, sizeof(path));
 535         memset(&ignores, 0, sizeof(ignores));
 536
 537         if (git_repository_is_bare(repo))
 538                 dir_flag = GIT_DIR_FLAG_FALSE;
 539
 540         if ((error = git_attr_path__init(&path, pathname, workdir, dir_flag)) < 0 ||
 541                 (error = git_ignore__for_path(repo, path.path, &ignores)) < 0)
 542                 goto cleanup;
 543
 544         while (1) {
 545                 /* first process builtins - success means path was found */
 546                 if (ignore_lookup_in_rules(ignored, ignores.ign_internal, &path))
 547                         goto cleanup;
 548
 549                 /* next process files in the path */
 550                 git_vector_foreach(&ignores.ign_path, i, file) {
 551                         if (ignore_lookup_in_rules(ignored, file, &path))
 552                                 goto cleanup;
 553                 }
 554
 555                 /* last process global ignores */
 556                 git_vector_foreach(&ignores.ign_global, i, file) {
 557                         if (ignore_lookup_in_rules(ignored, file, &path))
 558                                 goto cleanup;
 559                 }
 560
 561                 /* move up one directory */
 562                 if (path.basename == path.path)
 563                         break;
 564                 path.basename[-1] = '\0';
 565                 while (path.basename > path.path && *path.basename != '/')
 566                         path.basename--;
 567                 if (path.basename > path.path)
 568                         path.basename++;
 569                 path.is_dir = 1;
 570
 571                 if ((error = git_ignore__pop_dir(&ignores)) < 0)
 572                         break;
 573         }
 574
 575         *ignored = 0;
 576
 577 cleanup:
 578         git_attr_path__free(&path);
 579         git_ignore__free(&ignores);
 580         return error;
 581 }
 582
 583 int git_ignore__check_pathspec_for_exact_ignores(
 584         git_repository *repo,
 585         git_vector *vspec,
 586         bool no_fnmatch)
 587 {
 588         int error = 0;
 589         size_t i;
 590         git_attr_fnmatch *match;
 591         int ignored;
 592         git_buf path = GIT_BUF_INIT;
 593         const char *wd, *filename;
 594         git_index *idx;
 595
 596         if ((error = git_repository__ensure_not_bare(
 597                         repo, "validate pathspec")) < 0 ||
 598                 (error = git_repository_index(&idx, repo)) < 0)
 599                 return error;
 600
 601         wd = git_repository_workdir(repo);
 602
 603         git_vector_foreach(vspec, i, match) {
 604                 /* skip wildcard matches (if they are being used) */
 605                 if ((match->flags & GIT_ATTR_FNMATCH_HASWILD) != 0 &&
 606                         !no_fnmatch)
 607                         continue;
 608
 609                 filename = match->pattern;
 610
 611                 /* if file is already in the index, it's fine */
 612                 if (git_index_get_bypath(idx, filename, 0) != NULL)
 613                         continue;
 614
 615                 if ((error = git_buf_joinpath(&path, wd, filename)) < 0)
 616                         break;
 617
 618                 /* is there a file on disk that matches this exactly? */
 619                 if (!git_path_isfile(path.ptr))
 620                         continue;
 621
 622                 /* is that file ignored? */
 623                 if ((error = git_ignore_path_is_ignored(&ignored, repo, filename)) < 0)
 624                         break;
 625
 626                 if (ignored) {
 627                         git_error_set(GIT_ERROR_INVALID, "pathspec contains ignored file '%s'",
 628                                 filename);
 629                         error = GIT_EINVALIDSPEC;
 630                         break;
 631                 }
 632         }
 633
 634         git_index_free(idx);
 635         git_buf_dispose(&path);
 636
 637         return error;
 638 }
 639